Arduino-Zabbix-Agent

Using an Arduino Uno v3 and a Zabbix Server to monitor a data center environment.

It's a Zabbix Agent tested and running successfully.

• Materials
• Schematic
• More info
  • DHT11
  • DS18b20
  • PIR
  • Soil humidity sensor
  • Led
  • Observations
• How to use
• Keys used on Zabbix
• On the code
• Example

Materials:

• Arduino Uno v3
• Ethernet Shield
• Arduino Sensor Shield*
• DHT11 (or similar) and one 10k resistor
• DS18b20 (or similar) and one 4.7k resistor
• PIR (Passive infrared sensor/Motion detector)
• Soil humidity sensor
• One led and one 1k resistor

*A new shield may be built by yourself.

Schematic:

Schematic done using Fritzing.

More info:

DHT11

This sensor can measure the air temperature and humidity. It doesn't need to be calibrated. It is recommended to take 1 sample per second or less. It returns one int for each data. The temperature is in Celsius. A 10k resistor must be connected to pins Vcc and Signal.

DS18b20

This sensor is responsible for measuring the air temperature and returning a float. It is fast enough to take one sample for each Arduino cpu clock. It doesn't need to be calibrated and is water-proof. The library OneWire is used for reading its data. This means it is possible to connect multiple DS18b20 sensors on a single Arduino port. The temperature is in Celsius. A single 4.7k resistor must be conected between Vcc and the pin connected to one or more sensor.

PIR

Plug and play sensor. Doesn't need resistor or adjustments. Its signal must be connected to an Arduino port and that's all. Returns 1 when detects motion and 0 when nothing is detected.

Soil humidity sensor

Tricky sensor. It returns 1 when it's dry and 0 when it detects humidity. Its output is digital. The sensibility must be adjusted by turning a small screwdriver on the sensor.

Led

Be careful! Leds are extremely fragile. It needs a 1k resistor in series to make it work. The brightness may vary depending on the model and color. In this project, the led is turned on when the Arduino receives a command and is turned off when the value is returned to the server.

Observations:

Some results are kept for a few seconds to avoid oscillations from the sensors. For example, PIR may get a positive (motion) result and then a null (motion stopped) before Zabbix check. So its value is kept for a few seconds on 1 to allow Zabbix to have enough time to read it.

DS18b20 function is checked on every loop, but the sensors are read only once every 15 seconds. If the request is made on less than 15 seconds after the last one, it simply replies the variable value, making the response much faster.

All temperature are in Celsius. To convert to Fahrenheit:

Temp F = 1.8*(Temp C) + 32

How to use:

Check pins used. Upload the code to the Arduino. Add an item on Zabbix Server.

• Type: Zabbix agent.
• Key: The key for each sensor (q, w, e, r, t etc).
• It is recommended to check each item on not less than once a minute.

Keys used on Zabbix:

• q - soil humidity
• w - air temperature on DHT11
• e - air humidity on DHT11
• r - air temperature on DS18b20 with serial number ending with 17
• f - air temperature on DS18b20 with serial number ending with B6
• v - air temperature on DS18b20 with serial number ending with D3
• t - motion detector

On the code:

Set the IP address, the gateway and the MAC address to be used by the agent.

Check how many sensors will be used and add them to the code if necessary. To do this:

• Set a pin using #define.
• Write a function to read the sensor if necessary.
• Choose a letter to be used as a command for each sensor function. Make sure the letter is not used anywhere else!
• On parseCommand, add the function to be executed when receiving the command defined on the step before.

Pins 10, 11, 12 and 13 cannot be used. They are used by the ethernet shield.

Pin 3 is the led.

Pin 4 is the DHT11.

Pin 5 is one or more DS18b20 (using OneWire).

Pin 6 is the PIR.

Pin A0 is the soil humidity sensor.

Example:

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Zabbix Agent on Arduino Uno v3

By GabRF.com